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BACKGROUND

Application of controlled in vitro techniques can be used as a screening tool for the development of new hemostatic agents allowing quantitative assessment of overall hemostatic potential.

MATERIALS AND METHODS

Several tests were selected to evaluate the efficacy of cotton gauze, collagen, and oxidized regenerated cellulose for enhancing blood clotting, coagulation, and platelet activation.

RESULTS

Visual inspection of dressings after blood contact proved the formation of blood clots. Scanning electron microscopy demonstrated the adsorption of blood cells and plasma proteins. Significantly enhanced blood clot formation was observed for collagen together with β-thromboglobulin increase and platelet count reduction. Oxidized regenerated cellulose demonstrated slower clotting rates not yielding any thrombin generation; yet, led to significantly increased thrombin-anti-thrombin-III complex levels compared to the other dressings. As hemostyptica ought to function without triggering any adverse events, induction of hemolysis, instigation of inflammatory reactions, and initiation of the innate complement system were also tested. Here, cotton gauze provoked high PMN elastase and elevated SC5b-9 concentrations.

CONCLUSIONS

A range of tests for desired and undesired effects of materials need to be combined to gain some degree of predictability of the in vivo situation. Collagen-based dressings demonstrated the highest hemostyptic properties with lowest adverse reactions whereas gauze did not induce high coagulation activation but rather activated leukocytes and complement.

Endoscopic negative-pressure therapy (ENPT) is becoming a valuable tool in surgical complication management of transmural intestinal defects and wounds in the upper and lower gastrointestinal tract. Innovative materials for drains have been developed, endoscopic techniques adapted, and new indications for ENPT have been found. Based on our broad clinical experience, numerous tips and tricks are described, which contribute to the safety of dealing with the new therapy. The aim of this work is to present these methods. The focus is on describing the treatment in the esophagus.

Endoscopic negative pressure therapy (ENPT) has been adapted for upper gastrointestinal tract applications. More than 400 patients have already been treated with ENPT due to transmural defects in the upper gastrointestinal tract, with a success rate of 87%. The greatest experience exists for the treatment of anastomotic leakages and perforations of the esophagus. The ENPT is also used in the duodenum, pancreas and for complications after bariatric surgery. There are new indications that go beyond treatment in complication management. Innovative drainage types and endoscopic techniques have been developed that broaden the spectrum of applications. The aim of this article is to give an overview of the current status of ENPT in the upper gastrointestinal tract.

Objective:

Acne vulgaris (acne) presents with increased oil-sebum secretion and subsequent formation of comedones, papules, pustules and nodules. Skin cleansing is part of the daily routine to improve skin condition. A monofilament debridement pad has shown to be effective when used for wound debridement and skin cleansing in dermatological conditions. The pad may offer benefits when used for acne affected skin.

Methods:

The in vitro cleansing capacity of the monofilament fibre pad was analysed and compared with commercially available cosmetic pads. For this purpose, a sebum model consisting of glass plates coated with an oil-red-stained layer of artificial sebum was used. To gain clinical experience a case series evaluated cleansing efficacy of the monofilament debridement pad in combination with polyhexanide and sodium-hypochlorite based solutions. Over a period of four months, seven individuals suffering from retentive moderate facial acne who visited the dermatology clinic for their acne used the pad as necessary, ranging from twice weekly to daily, dependent on the sensitivity of the patient's skin condition.

Results:

The in vitro study exhibited a significantly better cleansing efficacy of the monofilament debridement pad compared with the cosmetic pads. After single use of the pad subject scores on sebum reduction revealed excellent/very good in 42.9% and acceptable in 57.1% of cases. After repeated use of the monofilament pads scores on sebum reduction of excellent/very good were given in 85.7% and acceptable in 14.3% of cases. Subject scored handling of the pad and comfort during use also received favourable ratings.

Conclusion:

These initial results show the potential of the monofilament debridement pad for cleansing of acne-prone and acne affected skin. More robust studies are needed to confirm these results.

A gastrointestinal (GI) transmural defect is defined as total rupture of the GI wall, and these defects can be divided into three categories: perforations, leaks, and fistulas. Surgical management of these defects is usually challenging and may be associated with high morbidity and mortality rates. Recently, several novel endoscopic techniques have been developed, and endoscopy has become a first-line approach for therapy of these conditions. The use of endoscopic vacuum therapy (EVT) is increasing with favorable results. This technique involves endoscopic placement of a sponge connected to a nasogastric tube into the defect cavity or lumen. This promotes healing via five mechanisms, including macrodeformation, microdeformation, changes in perfusion, exudate control, and bacterial clearance, which is similar to the mechanisms in which skin wounds are treated with commonly employed wound vacuums. EVT can be used in the upper GI tract, small bowel, biliopancreatic regions, and lower GI tract, with variable success rates and a satisfactory safety profile. In this article, we review and discuss the mechanism of action, materials, techniques, efficacy, and safety of EVT in the management of patients with GI transmural defects.

BACKGROUND

The pressure exerted by a compression device on a part of the body corresponds to the dosage of the compression therapy. Therefore, the pressure course under compression materials should be investigated in different clinical situations.

MATERIAL AND METHODS

Pressure measurements were carried out under different compression materials in lying, standing and walking positions within the framework of training, self-experimentation and in patients with venous leg ulcers.

RESULTS

The results showed that the pressure varied considerably depending on the material used, the firmness of application, the local configuration (body position) and the time interval between applications. A loss of pressure occurred under each compression therapy, especially under inelastic short-stretch material, mainly due to movement and edema reduction. This pressure loss is decisive for the timing of dressing changes and a reason for the good tolerance of high-pressure levels in mobile patients.

CONCLUSION

Low pressures are particularly suitable for edema reduction. Hemodynamic effects require higher pressures (60-80 mmHg). For this purpose, inelastic materials are preferred which enable lower pressures when lying down (40-60 mmHg). As compression bandages are too loosely applied by many users, pressure indicators on bandages or adaptive bandages with templates are helpful to apply the material with the correct pressure. As a consequence of these findings it is postulated that, at least in studies comparing different compression media, pressure measurements should be carried out in the future, whereby the measuring point and body position should be documented.

Background and study aims

Endoscopic negative pressure therapy (ENPT) is used to close transmural defects in the rectum and esophagus. Very few reports have described

ENPT to manage duodenal defects. This study was designed to demonstrate ENPT in a population of 11 patients with transmural duodenal leakages.

Patients and methods

The method of ENPT was adapted for duodenal use. Open-pore polyurethane-foam or a thin, open-pore double-layered film was wrapped around the distal end of a gastroduodenal tube. First, this open-pore element was placed on the inner wound in the duodenum with endoscopy. Second, continuous negative pressure of –125mmHg was applied with an electronic pump. Drains were changed after 2 to 7 days.

Results

Eleven patients were treated with duodenal leaks. Eight defects occurred after operative closure of perforated duodenal ulcers, papillectomy or stricturoplasty, one anastomotic leakage after Billroth – 1 distal gastric resection, one iatrogenic perforation in endoscopic retrograde cholangiopancreatography, and one by a surgical drain. Median duration of therapy was 11 days (range 7 – 24 days). Complete healing of defects was achieved in all patients.

Conclusion

ENPT is an innovative endoscopic alternative for treatment of transmural duodenal defects.

In the current first report, it is shown how a post-laryngectomy pharyngocutaneous fistula was successfully closed by endoscopic negative pressure therapy (ENPT; also termed endoscopic vacuum therapy, EVT). The duration of negative pressure treatment was 14 days. Up until now, ENPT has been used for treatment of transmural defects in the rectum and esophagus. The new endoscopic method can also be used in the ENT field for closure of pharyngocutaneous fistulas.

Non-adhering dressings are commonly used during granulation, tissue formation, and re-epithelialization. Elucidating cytotoxic effects and influence on proliferation/migration capacity of cells like fibroblasts is of interest. Dressings' effects were investigated by comprehensive in vitro approach: (1) MTT assay measuring cell viability after direct contact, (2) ATP assay determining effects on cell proliferation, and (3) scratch wound assay featuring an in vitro wound healing model. One cotton-based dressing with vaseline (vas) was included in the study and four polyester dressings containing vas and technology-lipido-colloid matrix (TLC), carboxymethylcellulose (CMC), hydrocolloid (HC), or glycerin (gly) as additives. A polyamide dressing with vas + CMC and three silicone-based dressings (AT, CC, M) were tested. Polyester + vas + CMC did not negatively affect cell viability or proliferation but it was found that fibroblast layers appeared more irregular with decreased F-actin network structure and tubulin density possibly leading to hampered scratch closure. Silicone AT, polyester + gly and polyamide + vas + CMC caused distinct cell damage. The latter two further reduced cell viability, proliferation and scratch healing. From the overall results, it can be concluded that cotton + vas, polyester + TLC, polyester + vas + HC and the silicone dressings CC and M have the potential to prevent damage of newly formed tissue during dressing changes and positively influence wound healing.